1. Field of the Invention
The present invention relates generally to a system for performing document services on mobile computing devices, and more particularly, to a system for alerting users of the mobile computing devices of updates to documents stored in a shared document repository using document tokens.
2. Description of Related Art
While the use of mobile computing devices is becoming more prevalent among mobile workers, transfer of document information between mobile computing devices is often limited due to inadequate storage capacity on such devices or due to inadequate communication channel bandwidth. To overcome these limitations, many mobile workers carry a laptop computer with them while traveling. Although laptop computers are increasingly smaller and lighter, their functionality, which is designed to meet the requirements of office-based document work, is determined largely by the desktop machines from which they evolved. Powerful editors and spreadsheet applications, for example, that are essential in certain office-based work environments have limited utility while away from the office. In some circumstances, mobile workers carry laptop computers simply to be able to access their documents, and not necessarily to create or edit them.
One mobile document transaction service for overcoming these limitations is disclosed in U.S. Pat. No. 5,862,321 (published also as European Patent Application EP 691,619 A2). More specifically, U.S. Pat. No. 5,862,321 (entitled: xe2x80x9cSystem and Method for Accessing and Distributing Electronic Documentsxe2x80x9d) discloses a system for transferring between computers document identifiers that represent a particular document, rather than the document itself. This system can include any number of workstations, file servers, printers and other fixed devices (including multifunction devices) coupled to a network, as well as a number of mobile computing devices carried by users and coupled to the network by an infrared (IR) or radio (RF) link. Each mobile computing device appears to hold a user""s personal collection of documents, with the devices being programmed to receive, transmit, and store document identifiers (e.g., a URLxe2x80x94xe2x80x9cUniform Resource Locatorxe2x80x9d) or document tokens, as defined herein.
Each document token is associated with an electronic document stored in an electronic repository or database. The mobile document transaction service effectively distributes references to documents between mobile computing devices by transmission of document tokens, rather than the documents themselves. For example, a document can be sent to an IR transceiver equipped network printer by xe2x80x9cbeamingxe2x80x9d a document token, which references the document, from a mobile computing device to the network printer. The network printer retrieves the complete document referenced by the document token, and immediately prints a copy of the document. Thus, to a user of the mobile document transaction service, documents are seamlessly passed between users and output or input to devices coupled to networks as expansive as the Internet. Since the document references are small and defined, the documents that they reference can have an arbitrary size and not impact the performance of the mobile computing devices. Advantageously, token based document references can be passed between two mobile computing devices without having to transmit large amounts of data.
Users of mobile computing devices often operate in a collaborative setting where they are required to share a collection of documents that is stored in a central repository. These documents often set forth information that is updated and managed by one or more persons with access to the central repository. Once updated, the documents must be distributed as quickly as possible to the mobile users. Accordingly, it would be desirable to provide a system that automatically notifies mobile users of updates to documents stored at the central repository. Furthermore, it would be desirable that such a system provide the mobile users with means for utilizing available document services to either print, display, or forward the updated documents upon receipt of such notification. Such a system would advantageously eliminate the need for users of mobile computing devices to check whether changes have been made to information stored at the central repository. In addition, such a system would advantageously enable the users of the mobile computing devices to utilize document services available on wire-based networks without ever having to retrieve the updated information received from the central location to their mobile computing device.
In accordance with the invention there is provided a method and apparatus therefor, for operating a token-enabled server coupled to a network. The token-enabled server receives a first set of data identifying a set of mobile computing devices. The first set of data provides the token-enabled server with addresses for communicating with each mobile computing device in the set of mobile computing devices over a wireless communications transceiver system. The token-enabled server receives a second set of data identifying a set of document elements. The set of document elements received by the token-enabled server defines locations of documents stored on the network. Subsequently, the token-enabled server defines a lookup table using the first set of data and the second set of data. The lookup table is used to associate at least one document element in the set of document elements with at least one address identifying one of the mobile computing devices in the set of mobile computing devices. The token-enabled server then spawns a process for monitoring modifications to documents identified by the set of document elements. Using the spawned process, the token-enabled server observes modifications to the documents identified by the set of document elements. In response to observing modifications to the documents, the token-enabled server transmits a notification message to each mobile computing device associated with the document element corresponding to the modified document using the lookup table.